<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>基于弹性布局，实现典型的页面布局</title>
</head>
<body>
    <style>
         * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        .nav ,.footer{
            width:100%;
            height: 50px;
            background-color: rgb(39, 78, 112);
            color: white;
            text-align: center;
            line-height: 50px;
            font-size: 20px;
        }
        .container {
            width: 100%;
            height: 600px;
            display: flex;
            justify-content: space-around;
            align-items: center;
        }

        .container .left, .container .right {
            width: 20%;
            height: 100%;
            background-color: rgb(219, 96, 96);
            font-size: 20px;
            text-align: center;
            line-height: 600px;
        }
        .container .center {
            width: 60%;
            height: 100%;
            background-color: rgb(119, 119, 209);
            font-size: 20px;
            text-align: center;
            line-height: 600px;
        }

    </style>
    
    <div class="nav">导航栏</div>
    <div class="container">
        <div class="left">
            左侧边栏
        </div>
        <div class="center">
            内容区
        </div>
        <div class="right">
            右侧边栏
        </div>
    </div>
    <div class="footer">
        页脚
    </div>
</body>
</html>